Realize that God, in His mercy, will save them if you truly weep for them and pray to Him because you want to see them be saved, but who will save you?
>They don't deserve any sympathy, because holding sympathy enables them even more.
You do not bring people to salvation by treating them like demons, who cannot be saved, but by treating them like icons of God. Icons of God that may be covered in mud and feces, but icons of God nonetheless. They are victims of the devil, they are not free in Christ, but slaves to sin. As cliché and misunderstood as "love the sinner, hate the sin" can be, it remains nonetheless correct - you do not bring individuals to salvation by being blind to the distinction between their person and their sinfulness, even if they themselves are blind to it.
If they see any attack on their sinfulness as an attack on their person, then let the light of Christ shine through you, so that they may see that God truly works through His servants, and that He truly is love, humility, and salvation, and that a Christian lifestyle of perfection is the only way to avoid Gehenna, and most importantly, that committing sin is antithetical to this.
So, you have to not only cease to spite them, but you have to even love them. Our Lord, the only perfectly pure man because He is God, laid His life down for the sake of generations upon generations of sinners who deserve nothing less than eternal punishment. And we are expected to love the creation of God just as much as He has shown He does, and anything less than that will bring swift and eternal judgment upon us.
I suggest the first step toward loving others would be to speak of them with more compassion. "Roasties"? Language is a powerful thing, even in our private thoughts. As our Lord said, anybody who says to his brother "Raka" will be liable to eternal fire.